(1) Field of the Invention
The present invention relates to in-line mixers of the type which are inserted in a pipeline to stir and mix the material flowing through the pipeline and more particularly, to an in-line mixer having mixing means disposed within a rotationally driven hollow cylinder so that the mixing means mixes and stirs the material as it flows through the inside of the rotating hollow cylinder.
(2) Background Information
There are numerous industrial applications which require the transporting of material through a pipeline from one location to another. It is frequently necessary to effect mixing of the material during its flow through the pipeline, and one means for accomplishing such mixing is to insert a mixer in series along the length of the pipeline. Such mixers are called in-line mixers as they are inserted directly in the pipeline.
One common type of in-line mixer is the so-called static mixer which comprises a housing dimensioned to be fitted in a pipeline and which contains therein a stationary mixing element. The mixing element generally has a plurality of stationary flights for deflecting the flowing material to cause the same to flow radially inwardly and outwardly during its advancement through the housing thereby effecting mixing of the material. In use, the static mixer is inserted in a linear section of a pipeline so that the flowing material enters one end of the housing, undergoes mixing by the stationary mixing element during its advancement through the housing, and exits the other end of the housing into the pipeline.
Under ideal conditions and using an ideal fluid as the flowing material, the static mixer can theoretically attain a uniform radial flow of the fluid together with thorough mixing, good heat conduction and the like. However, in actual practice, ideal conditions do not prevail. Thus, in practice, such a static mixer does not achieve uniform mixing, and stagnation regions form along the pipe wall within the housing. In the case of fluids having low Reynolds numbers, such fluids do not flow easily and considerable stagnation occurs, and such results in inadequate and non-uniform mixing of the fluid.